From dcc17d1baef3721d1574e5b2f4f2d4607514bcff Mon Sep 17 00:00:00 2001 From: Peter Keilty Date: Mon, 31 Oct 2005 16:44:47 -0500 Subject: [IA64] Use bitmaps for efficient context allocation/free Corrects the very inefficent method of finding free context_ids in get_mmu_context(). Instead of walking the task_list of all processes, 2 bitmaps are used to efficently store and lookup state, inuse and needs flushing. The entire rid address space is now used before calling wrap_mmu_context and global tlb flushing. Special thanks to Ken and Rohit for their review and modifications in using a bit flushmap. Signed-off-by: Peter Keilty Signed-off-by: Tony Luck --- include/asm-ia64/mmu_context.h | 19 +++++++++++++++---- include/asm-ia64/tlbflush.h | 1 + 2 files changed, 16 insertions(+), 4 deletions(-) (limited to 'include/asm-ia64') diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h index 8d6e72f7b08..8d9b30b5f7d 100644 --- a/include/asm-ia64/mmu_context.h +++ b/include/asm-ia64/mmu_context.h @@ -32,13 +32,17 @@ struct ia64_ctx { spinlock_t lock; unsigned int next; /* next context number to use */ - unsigned int limit; /* next >= limit => must call wrap_mmu_context() */ - unsigned int max_ctx; /* max. context value supported by all CPUs */ + unsigned int limit; /* available free range */ + unsigned int max_ctx; /* max. context value supported by all CPUs */ + /* call wrap_mmu_context when next >= max */ + unsigned long *bitmap; /* bitmap size is max_ctx+1 */ + unsigned long *flushmap;/* pending rid to be flushed */ }; extern struct ia64_ctx ia64_ctx; DECLARE_PER_CPU(u8, ia64_need_tlb_flush); +extern void mmu_context_init (void); extern void wrap_mmu_context (struct mm_struct *mm); static inline void @@ -83,9 +87,16 @@ get_mmu_context (struct mm_struct *mm) context = mm->context; if (context == 0) { cpus_clear(mm->cpu_vm_mask); - if (ia64_ctx.next >= ia64_ctx.limit) - wrap_mmu_context(mm); + if (ia64_ctx.next >= ia64_ctx.limit) { + ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, ia64_ctx.next); + ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap, + ia64_ctx.max_ctx, ia64_ctx.next); + if (ia64_ctx.next >= ia64_ctx.max_ctx) + wrap_mmu_context(mm); + } mm->context = context = ia64_ctx.next++; + __set_bit(context, ia64_ctx.bitmap); } } spin_unlock_irqrestore(&ia64_ctx.lock, flags); diff --git a/include/asm-ia64/tlbflush.h b/include/asm-ia64/tlbflush.h index b65c6270272..a35b323bae4 100644 --- a/include/asm-ia64/tlbflush.h +++ b/include/asm-ia64/tlbflush.h @@ -51,6 +51,7 @@ flush_tlb_mm (struct mm_struct *mm) if (!mm) return; + set_bit(mm->context, ia64_ctx.flushmap); mm->context = 0; if (atomic_read(&mm->mm_users) == 0) -- cgit v1.2.3